In general, wastewater includes nitrogen ingredients such as nitrate nitrogen (NO3−—N), nitrous acid nitrogen (NO2−—N), ammonia nitrogen (NH3—N, NH4+—N) and nitrogen ingredients of cyanogen (CN−) state, and organic materials of BOD (Biological Oxygen Demand) and COD (Chemical Oxygen Demand) induction ingredients. Accordingly, a water treatment apparatus and a water treatment method are required to remove these materials before the wastewater is discharged.
In the case of the water treatment apparatus and method, a biological treatment method is recommended to remove nitrogen ingredients. However, since the treatment cost is high, and the reaction time is long, there is a problem that the whole facility becomes large. In addition, the running condition is complicated by the hydrogen ion concentration (pH) control, or temperature or wastewater ingredients. Since microorganisms are extirpated in the case of wastewater containing poisonous materials or toxicants such as heavy metals or chloride ions, there is a problem that the kinds of wastewater to which the biological treatment method can be applied are limited.
In addition, an electrolytic device of the existing electro-chemical water treatment apparatus uses an electrode plate of a general metallic material, but such an existing electrode plate does not fulfill the demand for developing a recent new electrode plate that can improve electric power expense curtailment, durability, corrosion-resistance, abrasion-resistance, chemical resistance and life.
Further, in the case of the electro-chemical water treatment method of wastewater, efficient pre-treatment and post-treatment processes need to be systematically introduced in correspondence to components and states of wastewater, in order to treat various kinds of wastewater.